Re: [fluid-dev] Short note durations on percussion channel

[josh]

In a recent case, a user sent me a MIDI file that had 4 to 5ms  
duration percussion notes.  A lot of this is snare notes.  I tested it  
with your GeneralUser GS and most of the percussion track is missing,  
because of the short duration notes.  We've had this complaint a lot.   
I know that just having FluidSynth ignore note-offs for channel 10  
(#9) is of course not the answer, because a lot of people, me  
included, aren't even using GM/GS banks.  I was suggesting that there  
is a GM/GS mode, which has this behavior, but only gets turned on if  
the appropriate SYSEX message is received, or the user overrides it.

Of note is that the MIDI file that I received, does have GS reset  
SYSEX commands embedded in it.

From what I can tell though, there are MIDI files and MIDI equipment  
(drum pads) which expect percussion instruments to be one shot and not  
respond to note-offs.  We need to handle this somehow, if FluidSynth  
is going to faithfully playback these MIDI files.

Josh


Quoting "S. Christian Collins" <address@hidden>:

> My 2 cents: I'm pretty sure the Creative synths don't ignore note-off,
> and I don't think it's necessary, because this should be taken care of
> in the SoundFont design, IMO.  In the SoundFont's percussion bank, the
> release phase of each sample allows the drum to be sustained even when
> the note is released very quickly, and this is how GeneralUser GS and
> pretty much every other GM bank behaves.
>
> The problem with ignoring note-off events is that some percussion
> instruments really need to have duration control by the keyboard, such
> as the TR-808 bass drum in GeneralUser, which has a different response
> whether the key is held down or not.  Also, we can't guarantee that
> something loaded into the percussion preset pool will use a
> GM/GS-compatible key mapping.
>
> -~Chris
>
> address@hidden wrote:
> > I think the short note duration ticket should be fixed before 1.1.0  
> >  is released (I seem to remember David suggesting this too?).  I   
> > just found a PDF file called GM Guidelines Version 2.
> >
> > http://www.midi.org/techspecs/gmguide2.pdf
> >
> > On page 20, there is a section on response to Note-off on Channel   
> > 10.  It specifically mentions that GM percussion instruments should  
> >  ignore note-off events.  The exceptions being long Whistle and  
> > long  Guiro.  So that probably answers why there are MIDI files  
> > floating  out there with very short duration percussion note  
> > events.  I think  this also applies to GS.
> >
> > Now the question becomes, what is the best way for FluidSynth to   
> > handle this?  It would be nice to have a MIDI mode setting, which   
> > would respond to SYSEX messages which enable/disable GM and GS.    
> > I'm not sure if we should try and tackle that by 1.1.0 though.  I'm  
> >  not sure if every GM/GS file has the proper SYSEX messages either,  
> >  although we could let the mode be specified manually.
> >
> > Perhaps something like this would be adequate:
> > midi.mode = raw, gm, no-off-percuss
> >
> > raw: Don't do any special percussion channel handling
> > gm: Ignore note-offs for all but fast Whistle and Guiro on   
> > percussion channel
> > no-off-percuss: Ignore all note-offs on percussion channel
> >
> >
> > Any better ideas or suggestions?
> >
> > Josh
> >
> >
> >
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